


Drinking Gasoline

by EvergreenEmerald



Series: Smut dump [1]
Category: Undertale (Video Game)
Genre: Alcohol, Alternate Universe - Underfell, Biting, Break Up, Cheating, Dirty Jokes, Dirty Talk, Doggy Style, Dom Sans, Drunk Sex, F/M, Oral Sex, Rebounds, Underfell Sans
Language: English
Status: Completed
Published: 2016-11-20
Updated: 2016-11-20
Packaged: 2018-09-01 05:55:59
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,197
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8611381
Author URL: https://archiveofourown.org/users/EvergreenEmerald/pseuds/EvergreenEmerald
Summary: You find out that your boyfriend is actually engaged to another woman. Needless to say, you were pretty pissed off and depressed about being made the "other woman". You took time off work to wallow in your own sorrow by drinking as much as you could. Then an edgy skeleton hears about your breakup, comes over with a big bottle of Grillby's original whiskey, and an unexpected good time.





	

**Author's Note:**

> random smut oneshot that has been in my head for awhile. I mainly write kind of fluffy stuff and have only written three smuts before so this was my first "just cause i felt like writing smut" smut and was kind of practice for me, I guess. Though I did not plan for it to be so long....
> 
> I hope you enjoy and let me know if you notice any errors.
> 
>  
> 
> also, drink responsibly.

_“It’s not you, it’s me.”_

_“No fucking shit! You used me!”_

_“I broke under the pressure, I’m sorry.”_

_“Cheating on your fiancé is not breaking under pressure, you asshole! I have half a mind to go tell her what you did!”_

_“Are you sure that is a good idea babe? Do you really want to be known as a homewrecker?”_

_“You guys aren’t married yet; I’ll save her from future pain.”_

_“Ah, but here is the thing… she’s pregnant.”_

_“…what?”_

_“Yup, my beautiful bride-to-be has a bun in the oven. I know you and I know you wouldn’t want that kid to grow up with divided parents. So you won’t tell her shit.”_

_“You are a disgusting pig.”_

_“Yeah, so I am getting married next week so I figured I end what I had with you now. I’d invite you to the wedding, but that would make things awkward.”_

_CRASH_

_“Get. Out. Now.”_

 

* * *

And that is how your boyfriend of six months broke up with you. You have such shitty taste in men, you deserve a fucking award. You have dated some pretty bad guys before, but this guy was the worst. Even more upsetting is that he was actually a friend of yours for years. He came up to you saying that he had a crush on you for a while and wanted to be more than friends. You gave it a shot thinking what could go wrong… well, turns out he has been dating this other girl for much longer than you, even popped the question before asking you out. Now she is going to have his kid… it was all too much. You went on a drinking binge. Your boss called after not hearing from you for two days. You told Grillby everything about what happened, while hung over still. He gave you a week off and then proceeded to ask if you would like him to burn your ex to a fucking crisp and serve him as human barbecue to his customers. Grillby is a scary and very intimidating fire monster, but he has this gentle, caring side to him that he will deny till he turns to ash.

 

You are working on your next buzz while lying on your couch, flipping through channels for something to watch. You don’t actually feel like watching anything in particular, but you just can’t take the constant silence in your apartment. You start to hear a little voice in your head telling you how much of an idiot you are and that you were the other woman. That is not a good feeling; it might even be worse than being cheated on. You were used as a tool to hurt someone in one of the most painful and personal ways, you understand what that felt like and now you might be the cause of another poor woman’s pain. It made you feel sick and hate yourself for being so stupid. You chug your drink and moved on to the next. You are four drinks in and still not even close to being tipsy. You could go to Grillby’s to get drunk on the monster drinks, but that would involve you getting your ass off this couch and that is not happening anytime soon. Sighing, you sit up and open the next drink when you hear someone knocking on the door. You groan as you drag a hand down your face. “Fuck off! I’m not in the mood!”

 

“That’s not how the game works girly.” Ugh, it’s fucking Sans… It’s not like you don’t like the guy, you actually really like him and look forward to him coming to the bar to tell you one fucked up joke after the other. He always makes jokes saying that you are the reason that he comes to Grillby’s bar more often.

 

“Go away Sans!” You get up and make your way to the door and look through the peephole. Sans is standing there, awkwardly scratching his sweaty skull and a hand behind his back.

 

Sans reaches up and knocks on the door again. “Come on sweetheart. Knock knock.”

 

You groan, turning your back to the door and lean against it. You take a swig from your drink and slide down to the floor. “Who is fucking there?”

 

“Beat.”

 

“Beat who?”

 

“Who is the asshole that I have to beat up that hurt you?”

 

You chuckle. From the anger in his voice, you can clearly picture his one eye blazing with red magic. “No Sans. He isn’t worth it…”

 

“But you are.” Oh, well that took you by surprise. Either you are blushing or the alcohol is finally kicking in. You take another sip. “Knock knock.”

 

“Who’s there?”

 

“Asshole.”

 

“Asshole who?”

 

“Mind opening the door for this asshole?” You can’t help but to laugh at that. You are fully aware that he can just teleport inside if he wanted to, yet he was nice enough to ask for permission to come inside. These monsters all can’t seem to accept the fact that they are actually nice under all that edginess.

 

You slowly stand up and unlock the door. “Sure, come on in.” You smile at Sans, who seemed to completely relax as soon as you smiled at him.

 

“Whoa ___, you look like crap and smell like cheap beer. Good thing I brought the good shit.” Sans gave you a big sharp toothy grin as he held up a large bottle of Grillby’s original firewhiskey from behind his back.

 

You laugh and take the drink from him. Opening it, the fumes hit you strong like gasoline. This was definitely the good shit. “I knew there was a reason I liked you. Come on in and drink with me.”

 

* * *

 

You and Sans are pretty much wasted. Over half of the bottle is empty now and you are both swaying in your seats on the couch.  Currently you guys are in the middle of a dirty joke war. “Okay, I gotss one. Knock knock.” Sans drunkenly started the next joke.

 

You down another shot and reach for another. “Who’ss there?”

 

“Jenny Tull.”

 

“Jenny Tull who?” You take a sip of your drink as he leaned in.

 

His smile widened, his gold tooth glistening with leftover liquor. “Jenny tull warts.”

 

You do a spit-take and whiskey starts spilling down your chin. “Holy sshit…” You wipe off your chin and turn to look at him. “My turn. Knock, Knock.”

 

Sans turns towards you after refilling his glass. “Who's there?”

 

 “Anita.”

 

“Anita who?”

 

You smile slyly at him, licking your lips. “Anita Dick inside me.” Sans starts snorting as he hunches over.

 

“Good one sweetheart. ‘lright, Knock Knock.”

 

“Who's There?”

 

“Hop on.”

 

“Hop on who?”

 

“Hop on dis dick.” Sans makes a suggestive gesture to his crotch.

 

“Hah hah, nice. Knock Knock.” You scoot closer to him as you finish off your drink.

 

“Who's There?”

 

“Ben.” You chew on your lip in anticipation.

 

“Ben who?”

 

You lean over and whisper in where his ear should be in the most seductive voice that your intoxicated self could muster. “Ben me over and give it to me doggy style.” You can visibly see him shudder as you lean back to your original position. He looks completely shocked and you start to laugh more loudly. You gave him a triumph smirk, knowing that you got to the edgy skeleton

 

Sans throws back his drink and finishes it in one go. “Knock, Knock.”

 

Damn it, you were hoping to win for once. “Who's there?”

 

You turn away from him and place your glass on the coffee table to refill it. “Ivana.”

 

“Ivana who?” You almost drop your glass when you look back at him.

 

Sans’ eyes are full of lustful hunger. He speaks in a deep gravelly voice that almost sounded like a growl as he finished the joke. “Ivana fuck you so hard that you can’t walk straight for a week.”

 

You involuntarily gulp and eyed him. Was he serious? It’s not like you haven’t thought about it, it was more of curiosity of if he could have sex. Sans occasionally would flirt with you and make sexual comments that you always just pushed to the side. You never acted on anything because of your boyfriend… Nothing is really stopping you now… other than the fact that you are both clearly drunk and should probably not be making decisions like this. But does he really want to with you, a human? You looked back at his face and he was staring you down. You can feel the desire, _the need_ , from how intense he is looking at you. He is practically already undressing you with his eyes. You suck in a breath and chew on your lower lip. Nervously, you finally reply. “Why don’t you?”

 

He looked kind of shocked at you, not sure what he was supposed to do. You lock eyes with him, tension filling the air. He didn’t make any indication of moving, so you made the first move. You get on your hands and knees and crawl closer to Sans on the couch. “Don’t start somethin’ ya can’t stop sweetheart.” Sans growled at you. You only paused for a second before continuing to get closer to him.

 

“What would I start?” You are eyeing his body, wondering what you will see underneath his red sweater and basketball shorts. Placing your hand on his leg, you looked him dead in the eyes as you started to stroke his femur. “And would I really want it to stop?” You lower yourself to the floor, sitting between his legs. Your chin resting in his lap and a hand wanders to his shirt. “I was always curious, are you really all bone underneath here?”

 

“Ya know curiosity killed the cat, kitten.” He strokes you underneath your chin.

 

“But satisfaction brought it back.” You hum and grab his hand to examine it. Where you would think to see joints or gaps between the phalanges was actually bone. It seems, to make up for the lack of muscle and nerves, his bones were bigger and fused together with movable parts. Very different when compared to a normal human skeleton… well from what high school biology taught you. You wonder if the rest of him was like that. Looking back at his face, you could see his skull sweating more than usual. How does he sweat, does he have pores? You bring his hand closer to your face, dragging your lips across his thumb and then proceed to press it into your mouth. You could hear his bones quake as you explored his boney thumb, rubbing it against your hot tongue and occasionally sucking on it. He slowly pressed his thumb deeper into your mouth, pushing your tongue around and feeling around. You let go of his thumb with a pop, a trail of saliva still connecting your mouth to his hand. “Though, the real question is, can you satisfy this pussy?”

 

“I… holy fucking shit… uh…” Sans pulled at the collar of his shirt nervously, his cheekbones turning red.

 

You raise an eyebrow at him. Are you intimidating Mister Skeleton McEdgy? “Sans…” He looks back at you as you take off your shirt. His face becomes even redder. “Your turn.” You tug at his shirt for him to take it off.

 

“Are you sure about this dollface? I can’t make any promises, generally because I don’t like or care to.” He lifts his shirt off, despite trying to discourage you from continuing. You are entranced by his bones. They are definitely different from a human's’, much bigger and sturdier looking. You reach up and gently trace his sternum with your fingertips. You lean forward, resting your chest in his pelvis as you take a closer look. You can almost hear a buzz coming off his bones, probably the magic keeping them together. You let your hands drag around his bones, paying more attention to spots that make him shudder and sputter out profanity. You make your way down to his vertebra and press your lips to one of his ribs. He moaned above you.

 

“Sensitive?” You teased, feeling a little braver.

 

He grumbled above you, squirming from every stroke. “Either use that mouth to get me off or don’t make a sound, either way, shut the fuck up.” A red tongue sweeps across his teeth. He looked like he was ready to attack you any moment. You enjoy that you are the cause of that hungry look.

 

You smirked at him before continuing. You started to suck on one of his lower ribs while your hands stroked his spine. He began to pant above you, groaning once in awhile. Reaching down, you started to rub your thumbs into his hip bones on both sides, causing him to roll his pelvis into you. Something is now pressing into your chest. Oh, so he does have one. Well he does have a tongue obviously, why not a dick? Without looking at him for permission, doubting you needed to, you pulled down his pants. “Cool…” Just like his tongue, a glowing red cock stood strong and thick in front of you. You watched the red magic swirl around; it was actually kind of pretty and entrancing. But the glowing also reminded of you of a light-up dildo you have seen online, which you always questioned what the point of it lighting-up was.

 

Sans growled at you as you giggled. “You gonna do something or what?” He gripped your hair, pulling you closer.

 

“I was just admiring it, sheesh. I get it.” You lean over and gently press your tongue against the base of the cock; slowly you dragged your tongue up to the tip. It felt so smooth against your mouth, almost like it was glass. He sucked in his breath as you swirled your tongue around the tip, his grip on your hair tightened. You take the tip inside your mouth and began to suck.

 

You can hear Sans panting above you as you start to flick your tongue around his sensitive spots. Using both hands, you start to jack him off as you sucked harder on the tip, your tongue still swirling around. “Ssshiiiiiittt…” Suddenly, he starts thrusting into your mouth, shoving himself to the back of your throat. You had to let go of his cock to steady yourself, placing your hands on his femurs as he fucked your mouth. He used your hair like a handle to pull your head up and down. It took you a moment to get your gag reflex under control, but once you got into the fast rhythm of it, you started to enjoy it more. You can feel your underwear becoming completely soaked and you needed to be touched. Reaching around your back, you unhook your bra with one hand, freeing your breasts. You start to massage one of your breasts, tweaking your nipple and causing you to moan. Sans growled again and yanked your head completely off his dick. Drool and precum ran down your chin. You looked at him in confusion as you panted. “I won’t have any of that, only I am going to make you feel good. So don’t touch yourself, only me, capiche?”

 

You whimpered, rubbing your legs together for some kind of friction. “Then touch me.” You grab at his free hand and bring it closer to you. He lets you press his hand to your breast; he rubs his thumb against your nipple roughly. He grunts as you shiver against him. To your displeasure, he pulls his hand away.

 

“If you be a good girl, I might consider it. Now, take off your clothes and continue sucking me off.” You take your pants and underwear off and bend down in front of him. He holds up a hand. “No, on the couch, with that sexy ass of yours in the air.” You get on the couch and lean over to continue to blow him sideways. “Yeah, that’s a good girl. Such a pretty girl, sucking my cock so hungrily like that.” His hand made its way back in your hair, motioning you to go faster. You didn’t want to have a problem with your gag reflex again, so you use your hands to simulate what doesn’t go inside your mouth as you bob up and down. You are sloppily licking him everywhere, using your saliva as lube to help you stroke him with your hands. You can feel your core dripping now. You are starting to take him deeper when there is a sharp sting on your ass causing you to yelp. Sans had just spanked you, his fingers grazed against your opening that you have a suspicion that wasn’t an accident. “No one said you could stop. Keep fucking going.” He pushed your head down on him again.

 

You continue your work on his cock as he started to spank you again, harder each time. Once in awhile, his fingers would linger around your opening, teasingly. You started to sway your butt in a seductive manner, trying to get him to do more. “Oh, does my girl want more? Since you been so good, I’ll give you a reward. But that doesn’t mean you can stop. If you stop, I stop, got it?” You hum in agreement with his cock still in your mouth. “That’s what I like to hear.” He slowly slides a finger inside you. You suck on him hard, happy to feel something inside you. “You’re so wet. And your pussy is just eating up my finger so greedily, just like how you are doing to my cock right now.” He swirls his finger around, you take his cock in more deeply, practically swallowing the tip. He groans as he starts to move his finger faster. You start pushing into his hand for some more stimulation. “Is that not enough for you? You want more of my fingers inside your pussy?” You hum with him pressed against the back of your throat. “Then go fucking faster.” He roughly pulls your hair, but it isn’t painful. You start going faster as he commanded. You accidentally drag your teeth on him and think that he is going to stop, but actually he moans louder.

 

“Do that again kitten.” You comply, dragging your teeth up from the base and gently nibble at the tip, then swirled your tongue around at the tender parts. “Yeah, that’s right. Listen to every command I make. Such a good girl.” He has three fingers inside you now, swirling around at a fast pace and stretching you out for his thick girth. You moan and breathe heavily around his cock. “You feel so good kitten, all your holes are happily swallowing me all up.” You smile to yourself as he compliments you, moaning your name as you continue to deepthroat him, making his cock pulse faster. His thumb starts to rub against your clit as his fingers curled inside you. You moan loudly, taking his cock deep into your throat to the point that your nose is being pressed against bone. “Fuuuck…” He gasped.

 

He yanked your hair up, pulling you off his cock. You are both a panting and shaking mess. He takes his fingers out of your drenched core. You whimper from the lack of being filled. Staring you straight in the eyes, with his abnormally long tongue he licks your juices off his fingers, one by one. He holds out his wet fingers to you. “Suck.” You open your mouth and he shoves all three fingers inside. You tentatively suck and lick each finger, tasting a mixture of alcohol, yourself, and maybe a hint of mustard. “Turn around.” He lets go of your hair and you sit up on your knees, turning around like he told you to.

 

You feel yourself being pushed down, your face shoved into the cushions of the couch and ass in the air. You yelped in confusion and look back at Sans as he situated himself behind you. “You asked for this earlier, kitten. I’m only complying with your request.” He gave you a smug grin as he rubbed his tip against your opening; you bite your lip in anticipation and wiggle your hips closer to him. Without warning, he thrust himself completely inside you, hard. You moan loudly in pain and pleasure, before turning back to glare at him for entering too fast. He chuckles at you as he lays his body over you. “Now I’m going to… ah… fulfill my desire to fuck you… till you can’t walk.” He pulls back and slams into you again, this time you felt more pleasure than pain. He starts moving in an even pace, not letting up on you as you moan into a pillow.

 

He slaps your ass hard as he continues to thrust inside you. The harsh sting on your already bruising cheek caused you to shoot your head up as you moaned. “Don’t you fucking dare muffle your sweet moans. I want to hear you scream as I fuck you into oblivion. Come on, be a good girl and scream for me.” He slaps your ass again before gripping onto your hips to pull you harder into him.

 

“Oh fuck yess… Sanss…” You are moaning louder, letting yourself go and losing all sense of the world around as you started to meet his thrusts. All you cared about was the feeling of him inside you, making you drown in pleasure. Words are just spilling out of your mouth, asking him to go faster, harder, to keep going and never stop.

 

“Stars, how could I ever stop when you look like this? You look so beautiful as you lose yourself on my cock. And you feel so good around me, so hot and tight. I can barely pull out your pussy is holding so tight onto me, in fact I think it is pulling me back inside you.” He is becoming more erratic in his movements. “Man, I want to do this to you for so long… it’s better than all the sex dreams and fantasies I had of you put together.”

 

“You… ah, wanted me?” You asked between thrusts. Slowing down slightly, he yanks your hair up and makes you turn to look at him as he laid his body on top of you.

 

“More than you can fucking believe kitten.” He bites your shoulder, puncturing deep and making you scream. Blood pooled around on your skin and dripped down your arm onto the couch. He lapped at the blood and cleaning the wound he just caused. Your brain is completely clouded from a combination of lust, pain, and alcohol. “Blood or juices from your pussy, you are fucking delicious. Now I’m going to make you cum so hard that only I can ever make you feel this good.” He reached around your head and gently turned your chin towards him, pressing his blood covered fangs against your lips. You mindlessly respond to his gentle gesture of affection that seemed so out of character for him. Not like your mind is capable of fully comprehending what he was saying.

 

The kiss deepens as he continues shoving his cock inside you roughly. He lets go of your chin to start rubbing against your clit with one hand while another lifts your right leg up above his hip, giving him better access to hit your g-spot directly. You turn your body as he moved you. Balancing on one elbow, you link your right arm around his neck, holding him in place as you sucked his tongue into your mouth. Every swirl around your clit and hard thrust causes you to moan louder. Your walls hold tighter onto him, making him moan just as loud. The two of you had completely given into your lustful needs to cum, fucking hard and erratically. You can feel a blissful coil tighten around in your abdomen. “So close…” He is grunting and growling as he slams into you. “I’m going to cum inside you, is that what you want kitten? To be full of my hot cum?”

 

“Yes…” You desperately pull him closer.

 

“I don’t know what you are agreeing to kitten? Good girls tell me exactly what they want or else they don’t get it.” He slows down and chuckles at you as you whine. He really is cruel.

 

“Please Sans, please fill me up with your cum.” As soon as the words leave your mouth, he moves again, thrusting harder and deeper than before. You are screaming his name, begging him to make you cum. Finally, you feel yourself coming completely undone. Your vision becomes dotted with white spots as your muscles convulsed around him. The sudden tightness caused Sans to cum inside you. He continued to thrust inside as he rode out his orgasm at the end of yours. You both collapse onto the couch after coming down from your highs, panting and covered in sweat. “Wow…” You mumbled as your body relaxed into its afterglow.

 

Sans nuzzles into you, wrapping his arms around your waist. “Yeah, not bad for round one kitten.”

**Author's Note:**

> I'm going to hell! WooHoo! :3


End file.
